Handle for a hand tool

ABSTRACT

The invention provides a handle ( 38 ) for hand and garden tools which causes a preferred coupling position of an assigned group of hands when the respective tool is used. The handle ( 38 ) contains a first section for contacting the palm and a second section that is intended for being encompassed by the fingers. The first section contains a distal part ( 50 ) that is intended for being encompassed by the thumb bridge, a proximal part ( 54 ) that is intended for contacting the ball of the hand root and a center part ( 52 ) that lies between the two aforementioned parts and has a pronounced radially outward directed curvature that extends over at least part of its circumference and is intended for snugly adjoining the inner surface of the hand. The distance of this curvature from the longitudinal axis ( 39 ) is at its greatest in a maximum ( 59 ) that lies in a central region of the curvature and distinctly decreases from this location to the distal and the proximal part ( 50, 54 ). According to the invention, a length (L 0.1 ) of the center part ( 52 ) amounts to 45-55% of the hand width of the assigned group of hands and has a curvature—if viewed in a longitudinal section that contains the longitudinal axis ( 39 )—with a curvature radius (R 2.1 ) of 50-120 mm in the maximum ( 59 ). The invention also provides handle sets, hand or garden tools and hand or garden tool sets containing handles of this type (FIG.  5 ).

FIELD OF THE INVENTION

[0001] The invention pertains to handles for hand and garden toolsaccording to the preamble of claim 1, as well as to handle-and-tool setscontaining such handles.

BACKGROUND OF THE INVENTION

[0002] In the context of the present invention, the term handles forhand and garden tools refers to handles that cause a preferred couplingposition of the hand when the tool is used, i.e., the user preferablytakes hold of and encloses the handles with a specific hand positionthat depends on the handling of the tool while it is used, wherein thishand position changes only insignificantly while the tool is being used.This pertains, in particular, to handles that are centered in the handcavity approximately in the center of their longitudinal extent whilethe tool is used. Until now, handles of this type were manufactured inpreselected groups and shapes depending on the intended use of therespective tool, e.g., a handsaw or a file, and designed differently bythe various manufacturers. These designs are frequently realized inaccordance with given standards. In the product assortment of amanufacturer, only one respective handle is available for a tool of acertain type and size. This applies, in principle, independently ofwhether the tools have a one-part handle, e.g., for hammers, firmerchisels, files, mason's trowels, saws or the like, or a two-part handle,e.g., for pliers, pruning shears or similar tools of the pliers orscissor family.

[0003] The design of the handles as a function of the intended use ofthe respective tool should be done in accordance with ergonomicconsiderations, particularly if the tools are used professionally. Thisis the reason why it has already been investigated which couplingposition the hands should assume relative to the handles and whichdimensions ergonomically favorable handles should have [e.g., “ErgonomicTool Design, Systematic” (Research Report No. 156), published by theGerman Federal Institute for Occupational Safety and Accident Researchin 1979]. It is surprising that these investigations did not result inhandles that sufficiently take into account the anatomical peculiaritiesof the quite different sizes and/or shapes of the human hand. Forexample, a barrel shape with a curvature radius of 220 mm for thelongitudinal contour is proposed for grab handles (page 253). Acurvature radius of 220 mm is also proposed for pliers-like handles.These radii are too large, and do not result in an optimal contactbetween the handles and the hand. Handles that are known from the priorart and are available on the market also have not undergone additionaldevelopments. For example, hammer handles do not fill up the handcavity, and are even partially shaped in a concave fashion within thecontact region such that, in particular, the recoils occurring whilehammering are distributed over small and limited zones of the hand.Although saw handles are shaped in a convex fashion in the longitudinaldirection, the curvature radii are too large, and possibly-provideddepressions for the fingers are not appropriately designed. Althoughpliers frequently have convex or elliptical handle parts in thelongitudinal direction, most handles are too narrow and excessivelyshort such that the outer edges of the palm do not contact the handles,and the inner surface of the hand, as well as the middle joints of thefingers, are subjected to painful pressure in a narrow zone when thepliers are closed. The handles of firmer chisels (wood chisels) usuallyextend in a continuously conical or even concavely curved fashion in thelongitudinal direction. This completely contradicts the anatomy of theencompassing hand. Corresponding and additional deficiencies can also beobserved with all the tool handles.

[0004] Handles of the initially described type are explained in detailin prior applications of the same applicant (PCT/DE 00/00209 of Jan. 25,2000 and DE 199 02 882.6 of Jan. 25, 1999). Handles of this type shouldautomatically cause a preferred coupling position of the hand while therespective tool is used, and also make it possible to largelystandardize the handles in accordance with different handle sizes and/orhandle shapes. The essential elements of such handles are the respectivecenter parts, the upper and lateral sections of which are shaped suchthat they assume a centered position in the hand cavity while the toolis being used, and essentially fit closely against the entire innersurface of the hand. However, the above-mentioned older proposals do notcontain any specific information concerning which handles dimensionsneed to be influenced in order to achieve the desired effect. This alsoapplies to other known handle (PCT-WO 98/29167) which have certaincurvatures that fit into the hand cavity and are, in particular,characterized by special support surfaces for the thumb and trough-likereceptacles for the remaining four finger. Based on the aforementionedcircumstances, the invention aims to further improve handles of theinitially described type and to disclose those dimensions of the handleswhich most easily result in a preferred coupling position of the handand are suitable for a comprehensive standardization. However, thehandles are neither individually adapted to certain hands nor designedfor an “average hand.” On the contrary, the invention aims to sort andclassify measuring data obtained from hand measurements such that groupsof hand sizes can be formed therefrom.

SUMMARY OF THE INVENTION

[0005] This objective is attained with the characteristics disclosed inthe characterizing portions of claims 1, 28, 30 and 31. The invention isdescribed in greater detail below with reference to the embodiments thatare illustrated in the enclosed figures.

BRIEF DESCRIPTION OF THE INVENTION

[0006]FIGS. 1 and 2 are a schematic perspective representation and aschematic top view, respectively, of a section of an oval handle knownfrom the prior art, used to explain the terms used in the followingdescription.

[0007]FIG. 3 is a schematic representation of the inner surface of aright hand, used to illustrate the hand sections that are important forthe invention.

[0008]FIG. 4 is a cross sectional view through the hand along the lineIV-IV in FIG. 3.

[0009]FIG. 5 is a side view of a handle according to the invention for ahand tool in the form of a hammer.

[0010]FIG. 6 is a top view of the handle shown in FIG. 5.

[0011] FIGS. 7-10 are cross sectional views, respectively, through thehandle along the lines A-A, B-B, C-C and D-D in FIGS. 5 and 6.

[0012]FIG. 11 is a schematic side view of the handle according to FIGS.5-10 in connection with a hammer, and a hand that encompasses the handleand is situated in a preferred coupling position.

[0013]FIGS. 12 and 13 are schematic sectional views along the linesXII-XII and XIII-XIII, respectively, in FIG. 11.

[0014] FIGS. 14-18 are representations of a second embodiment of ahammer handle according to the invention which correspond to therepresentations in FIGS. 5-9.

[0015] FIGS. 19-24 are representations of a handle according to theinvention for a hand tool in the form of a mason's trowel whichcorrespond to the representations in FIGS. 5-10.

[0016] FIGS. 25-30 are representations of a second embodiment of ahandle according to the invention for a mason's trowel which correspondto the representations in FIGS. 19-24.

[0017]FIGS. 31 and 32 are schematic side views of the handles accordingto FIGS. 19-24 and FIGS. 25-30, respectively, with a hand thatencompasses the handle and is situated in a preferred coupling position.

[0018]33 is a schematic side view of a handle according to the inventionfor a hand tool in the form of a saw.

[0019]FIG. 34 is a front view of the handle according to FIG. 33 (viewedfrom the right in FIG. 33).

[0020] FIGS. 35-37 are cross sectional views through the handle alongthe lines A-A through C-C, respectively, in FIG. 33.

[0021]FIGS. 38 and 39 are schematic side views of the handle accordingto FIG. 33 in connection with a hand that encompasses said handle, withthe hand still being partially open in FIG. 38 and situated in apreferred coupling position in FIG. 39.

[0022] FIGS. 40-43 are schematic longitudinal section views through ahandle according to the invention that, in particular, is suitable for amason's trowel, along four different sectional planes that arerespectively rotated by 45°.

[0023]FIGS. 44a and 44 b are cross sectional views through the handlealong the lines A through T in FIG. 40.

[0024]FIG. 45 is a schematic representation of the position of the x, yand z coordinates of selected points on the surface of the handleaccording to FIG. 40.

[0025]FIG. 46 is a perspective grid representation of a handle thatessentially corresponds to FIGS. 40-45.

[0026]FIG. 47 is a side view of the handle according to FIG. 46 whichcorresponds to the side view shown in FIG. 5, in the form of a gridrepresentation.

[0027] FIGS. 48-50 are a top view, another side view after turning thehandle in FIG. 47 by 90° and a bottom view after turning the handleaccording to FIG. 47 by 180°, wherein the handle is rotated against theclockwise direction.

[0028]FIG. 51 is a side view of a handle according to the invention fora hand tool in the form of pliers.

[0029]FIG. 52 is a top view of the handle according to FIG. 51.

[0030] FIGS. 53-55 are cross sectional views along the lines A-A throughC-C, respectively, in FIG. 51.

[0031]FIG. 56 is a schematic representation of the handle according toFIG. 51 in connection with a hand situated in a semi-open position.

[0032]FIG. 57 is a representation of a hand, situated in a preferredcoupling position, that corresponds to the representation in FIG. 56.

[0033]FIG. 58 is a representation of the handle according to FIG. 51,essentially corresponding to the representation in FIG. 13, with a handthat encompasses the handle and is situated in a preferred couplingposition.

[0034] FIGS. 59-63 are representations of a second embodiment of apliers handle according to the invention that correspond to therepresentations in FIGS. 51-55.

[0035]FIGS. 64 and 65 are representations of a third embodiment of apliers handle according to the invention that correspond to therepresentations in FIGS. 51 and 52.

[0036] FIGS. 66-69 are schematic longitudinal section views through ahandle according to the invention which is, in particular, suitable fora hammer, along four different sectional planes that are respectivelyrotated by 45°.

[0037]FIG. 70 are cross sectional views through the handle along thelines A through L in FIG. 66.

[0038] FIGS. 71-73 are grid representations of the handle according toFIGS. 66-70 that correspond to the grid representations in FIGS. 47-50.

[0039]FIG. 74 is a perspective dot matrix representation of the handleaccording to FIG. 71.

[0040] FIGS. 75-83 are representations of a handle according to theinvention that is particularly suitable for a saw, with saidrepresentations corresponding to the representations in FIGS. 66-74.

[0041] FIGS. 84-92 are representations of a section of a handleaccording to the invention that is suitable for pliers, with saidrepresentations corresponding to the representations in FIGS. 66-74.

[0042]FIGS. 93a and 93 b are tables with dimensions for a preferredembodiment of the handle according to FIGS. 14-18.

[0043]FIGS. 94a and 94 b are tables with dimensions for a preferredembodiment of the handle according to FIGS. 19-24.

[0044]FIGS. 95a and 95 b are tables with dimensions for a preferredembodiment of the handle according to FIGS. 34-37.

[0045]FIGS. 96a, 96 b and 96 c are tables with dimensions for apreferred embodiment of the handle according to FIGS. 51-55.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0046]FIGS. 1 and 2 schematically show, in the form of an enlargedrepresentation, part of a conventional handle 1 that essentially extendsin a continuously oval fashion in the longitudinal direction and is, forexample, situated on the end of the handle of a hammer. An axis that isrespectively defined by the largest diameter in the cross sectionrepresents the x-axis, an axis that is respectively defined by thesmallest diameter represents the y-axis, and a central axis orlongitudinal axis that extends perpendicular to the two aforementionedaxes represents the z-axis. In addition, the height of the handle 1 ismeasured in the direction of the x-axis (dimension H), the thickness ofthe handle 1 is measured in the direction of the y-axis (dimension D),and the length of the handle 1 is measured in the z-direction (dimensionL). It is also assumed that the handle 1 is divided into a first outerhandle section 7, a second outer handle section 8 and a third handlesection 9 that lies between the two aforementioned handle sections andrepresents an inner handle section bounded by two imaginary planes 5, 6that are illustrated with broken lines and, for example, extend parallelto the zy-plane. These three handle sections lie adjacent to one anotherin the direction of the x-axis. This means that the first handle section7 has a first outer surface 10 that includes a first zone with smallcurvature radii, and that the second handle section 8 has a second outersurface 11 that is situated diametrically opposite to the first outersurface and includes a second zone with small curvature radii. Bycontrast, the third section 9 has two diametrically opposed surfaces,namely third and fourth outer surfaces 12 and 13, with large curvatureradii. These surfaces 12 and 13 respectively extend approximately up tothe intersection lines with the corresponding boundary planes 5 and 6that are indicated by the points 14, 15 and 16, 17, and representcontinuations of the contours formed by the surfaces 10 and 11. Thismeans that the entire outer surface contour has a continuouslyelliptical or oval cross section. It is also assumed that the handlesection 7 corresponds to the hand cavity of right-handed users, and thatthe surfaces 10-13 make contact with associated hand and finger regions.The handle 1 is, for example, realized in the form of a one-piece handleand is quite massive, with said handle being suitable, for example, fora hammer, a mason's trowel or the like. In this case, the height of thehandle section 9 may approach zero. However, if the handle consists of ahandle for pliers, which conventionally comprises two pivoted handlelimbs, it can be assumed for the purpose of the invention that onehandle limb is essentially realized by the section 7 in FIGS. 1 and 2,and that the other handle limb is essentially realized by the handlesection 8, wherein the inner section 9 is in this case omitted. Ifviewed in the direction of the x-axis, the sections 7 and 8 are spacedapart from one another by a distance that in this situation depends onthe type of tool. The height, the thickness and the length of suchtwo-part handles in the x-, y- and z-direction are indicated,analogously to FIGS. 1 and 2, by the dimensions H, D and L, or aredetermined from distance vectors as described in detail below. In theensuing figures, the boundary planes that divide the individual sectionsare at least partially indicated by broken lines, but are not mentionedfurther in other respects.

[0047] The parts of a right hand 19 that are important for explainingthe invention are illustrated in FIG. 3. According to this figure, thehand 19 contains a thumb 20 with a proximal thumb member 21 near thehand 19 and a distal thumb member 22 that is situated distant from thehand 19, as well as the other four fingers that respectively compriseproximal, central and distal finger members 23, 24 and 25. The hand 19also comprises a thumb saddle 26 between the thumb 20 and the indexfinger, an edge of the finger root 27, a ball of the thumb 28, a ball ofthe hand root 29 and a hand edge 30 with a ball of the hand edge 31. Thepart at which the fingers begin is referred to as the ball of the fingerroot 32, and the part circumscribed by the balls 28, 29, 31 and 32, aswell as the thumb bridge 26, is referred to as the inner surface of thehand or simply the palm 33. In the preferred coupling position, thispalm is deformed into a characteristic hand cavity about a center point34.

[0048] According to FIG. 3, the hand width is measured between the handedge 30 and the diametrically opposite edge of the finger root 27 in thevicinity of the thumb bridge 26, while the hand 19 is stretched out.This dimension is measured transverse to the longitudinal axis of thehand 19 as indicated by a line B in FIG. 3.

[0049]FIG. 4 shows a schematic section through the hand surface 33 alongthe line IV-IV in FIG. 3, with a schematically arranged handle 1according to FIG. 1. This indicates that conventional oval handles 1 donot fulfill the ergonomic requirements because they only contact thehand in the region of the palm 33 at narrow areas of the thumb bridge 26or the ball of the thumb 28, and at the ball of the hand edge 31, withthe handle not contacting the palm 33 in the regions situated inbetween.

[0050] FIGS. 5-10 show a handle 38 according to the invention that is,for example, suitable for a hammer. This handle is largely adapted tothe hand 19 according to FIGS. 3 and 4, and is preferably manufacturedin one piece. The handle 38 has a longitudinal axis 39 that essentiallycorresponds to the central axis of the handle 38 in this case. In thethat extends perpendicular to the longitudinal axis, the handle hascross-sectional surfaces that are essentially egg-shaped, elliptical oroval at all locations (FIGS. 7-10).

[0051] The longitudinal axis 39 may, for example, extend through thecenter points of circular end faces that are arranged on the ends of thehandle 38, with the longitudinal axis being arranged coaxial with thecentral axis of a receptacle opening that is intended to accommodate atool shaft, or it can be defined in some other way in the central handleregion. According to the aforementioned definitions regarding FIGS. 1and 2, the longitudinal axis forms the z-axis of an imaginary Cartesiancoordinate system. In sectional planes that are arranged perpendicularto the longitudinal axis 39 (e.g., FIGS. 7-10), the axes extendingthrough the largest diameter respectively lie parallel to the x-axis,and the axes extending through the smallest diameter lie parallel to they-axis of the imaginary coordinate system. This also produces thedimensions H and D. The dimensions measured in the direction of thez-axis are referred to in this case as the distances betweenpredetermined cross-sectional planes. The dimensions H and D of thehandle 38 have different values along the longitudinal axis 39.

[0052] In FIGS. 5 and 8, it is assumed that the handle 38 is dividedinto three sections 42-44 by two planes 40 and 41 that are indicatedwith broken lines, and each lie on one side of the yz-plane and parallelthereto. The sections 42 and 43 correspond to the sections 7 and 8 inFIGS. 1 and 2 and are referred to as the upper section 42 and the lowersection 43 in accordance with their position above and below theyz-plane. However, the section 44 that corresponds to the section 9 inFIGS. 1 and 2 is referred to as the inner section. The handle 38 is alsolimited on its distal end, is coupled to a functional part of thecorresponding tool and lies on the left in FIGS. 5 and 6, as well as onits opposite proximal end, by respective planes 45 and 46 arrangedperpendicular to longitudinal axis 39 (FIG. 5), such that the distancebetween the planes 45, 46 represents the total length of the handle.Between these planes 45, 46 respectively extend one distal end piece 48that borders on the plane 45 and extends up to a cross-sectional plane47, a distal part 50 that borders thereon and extends up to across-sectional plane 49, a center part 52 that borders thereon andextends up to a cross-sectional plane 51, a proximal part 54 that issituated adjacent thereto and extends up to a cross-sectional plane 53,and ultimately a proximal end piece 55 that borders on the plane 46. Itshould be clarified that all these parts are assumed to be divided intorespective upper, lower and inner or central sections by the planes 40,41 (FIG. 8), with the respective upper, lower and inner or centralsections forming the sections 42-44. Although the handle 38 may also berealized as hollow in its interior, it is preferably solid.

[0053] The surfaces of the upper, lower and inner sections 42-44 havethe contours shown in FIGS. 5 and 6 and the cross-sectional shapes shownin FIGS. 7-10, with the surfaces of the different parts or sectionsrespectively transforming into one another in an essentially smoothfashion. The cross section of the handle 38 has the egg shape shown inFIGS. 7-10. The center part 52 respectively has-if viewed in the form ofa longitudinal section-a surface contour that is designed in a more orless convex fashion over at least part of the circumference of the uppersection 42. The distal part 50 and the proximal part 54 essentially havea concave surface contour that also extends over at least part of thecircumference of the upper section 42. In this embodiment, all surfacecontours are designed to be convex or concave as can be ascertained, inparticular, from a comparison between FIGS. 5 and 6 and FIGS. 7-10. Thecross sections in FIGS. 7-10 also indicate that the height H and thethickness D of the handle 1 are greater in the center part 52 than inthe distal part and the proximal part 50 and 54. This means that asurface contour that extends in a concave-convex-concave fashion, alongthe longitudinal direction in the top view according to FIG. 6, results.For example, in a body that is rotationally symmetrical about thelongitudinal axis 39, a concave-convex-concave line 56 in FIG. 6 wouldrepresent a generatrix of the rotational surface of this body.

[0054] The distal end piece 48 is realized analogously to conventionalcollars that prevent the hand from sliding off the handle, and is lessimportant for the purpose of the invention. The distal end piece mayalso be entirely omitted, with the proximal end piece 55 having theshape of a more or less defined hemispherical cap, and also being lessimportant for the purpose of the invention.

[0055] In a handle for right-handed users, the center part 52 in theupper section 42 is, according to the invention, realized such that itfits closely against the inner surface 33 of the hand 19 (FIG. 3) of theuser while the handle 38 is being used and is situated in the handcavity. Consequently, the center part 52 in the upper section 42 isprovided with a curvature 57 (FIG. 8) that is distinctly directedradially outward and is pronounced in at least two directions thatextend perpendicular to one another. This curvature extends over atleast part of the circumference of the upper part 42 and is produced dueto the convex surface contour. When viewed from the distal end, thecurvature of the handle 38 for right-handed users lies on the left sideof the xz-plane.

[0056] The distal part 50 in the upper section 42 is designed to beencompassed by the saddle between the thumb 20 and the index finger(FIG. 3). This is why this region is, analogously to FIG. 5, providedwith a concave surface structure that also extends over at least part ofthe circumference of the upper part 42. By contrast, the proximal part54 in the upper section 42 is designed to contact the ball of the handroot 29 (FIG. 3). In accordance with FIGS. 5 and 6, this region also isdesigned in a concave fashion over at least part of the circumference ofthe upper part 42.

[0057] The surface contour of the lower section is preferably shaped asrequired for the encircling by the finger joints which occurs at thislocation, and for the trapezoidal inner contour of the encirclingfingers in a preferred coupling position of the hand.

[0058] The surfaces of the inner section 44 that correspond to thesurfaces 12 and 13 in FIG. 2 serve to connect the sections 42 and 43 asshown in FIGS. 7-10. They may contain corresponding concave and convexsurface contours in the longitudinal direction (z-axis) which transforminto the contours of the surfaces of the sections 42 and 43 in a smoothfashion.

[0059] The concave and convex surface contours can be defined bycurvature radii R1.1-R3.4 (FIGS. 5 and 6). For the purposes of thepresent invention, those curvature radii are of particular importancethat occur in the upper section of the center part 52 at the maximum orsummit 59 of the convex surface contour (sectional plane B-B in FIG. 5),and in the upper sections of the distal and the proximal parts 50, 54 atthe respective minimums 60 and 61 of the concave surface contour(sectional planes A-A and C-C in FIG. 5). A comparison between FIGS. 5and 6 shows that the cross-sectional planes that extend through thesemaximum 59 and minimums 60, 61 respectively have a different axialposition in the upper section 42 than in the lower section 43 (forexample, the maximum 62 in FIG. 5).

[0060] The curvature radii R2.1-R2.4 that are particularly important forthe purpose of the invention and would, in FIG. 8 in which they are notshown, lie on the top, the left, the bottom and the right in thecoordinate system shown if it were turned to the left by 90°,approximately define respective sections of a circular arc that lie inthe xz-plane (FIG. 6) in FIGS. 5 and 6. These sections of the circulararc may, viewed in the direction of the z-axis, extend over a longerdistance with an essentially constant curvature radius (e.g., R2.1) toboth sides of the maximums (e.g., 59) before this curvature radiusgradually decreases and the surface contours of the center part 52ultimately transform into the concave surface contours of the parts 50,54 at turning points. This not only applies to the four contour lineswith the radii R2.1-R2.4 which are shown in FIGS. 5 and 6 andrespectively lie in the xz-plane and the yz-plane, but also to the otherplanes that include the z-axis. For example, the turning points of thecontour line extending through the maximum 59 are defined in FIG. 5 bythe position of the cross-sectional planes 49 and 51. The transitionbetween the regions identified by the curvature radii R2.1-R2.4 arerespectively defined by analogous radii or curves that, depending onpracticality, may deviate from the radii R2.1-R2.4. The concave regionswith the curvature radii R1.1-R1.4 and R3.1-R3.4 preferably progressaccordingly.

[0061] The egg-shaped cross-sectional surfaces in FIGS. 7-10 can bedefined by radii RA.10-RC.13. The curvature radii RA.10, RB.10 and RC.10which respectively occur in the region of the sectional planes A-Athrough C-C, as well as in the maximum 59 and in the minimums 60, 61 inthe upper sections, are of particular importance for the purpose of thepresent invention. In addition, the radii RA.10-RA.13, RB.10-RB.13, etc,according to FIGS. 7-10 respectively lie in planes that extend parallelto the xy-plane, if turned to the left by respective angles of 90° inthe imaginary coordinate system. In this case, the letters A, B, and Cetc., indicate the sectional planes A-A, B-B, C,-C etc., in FIG. 5.Consequently, the aforementioned radii define sections of the circulararc which lie in these planes. Analogously to the radii R1.1-R3.4, thesections of a circular arc which belong to the radii RA.10-RC.13 may,when viewed in the planes that lie parallel to the xy-plane, extend overlonger arc sections with essentially constant curvature radii on bothsides of the maximums and minimums (e.g., 59 in FIG. 8). The transitionsbetween the regions identified by these radii are respectively definedby analogous radii or curves that, depending on practicality, may alsodeviate from the radii RA.10-RC.13. Similar observations can be made inan arbitrary number of additional cross-sectional planes along thelongitudinal axis 39.

[0062] In the longitudinal direction, the distances L0.1, LI.1, LII.1and LIII.1, which are shown in FIG. 5 and are described in greaterdetail below, are of particular importance for the handle 38. Thereference plane for these dimensions is the sectional plane B-B thatextends through the upper maximum 59 that lies in the xz-plane andotherwise lies parallel to the xy-plane, i.e., the maximum 59 on theupper side of the upper section 42 unequivocally defines the position ofthe reference plane 63. Its distance from the planes that extend throughthe minimums 60, 61 is defined, respectively, by the dimensions LI.1 andLII.1, wherein LIII.1 represents the distance of the reference plane 63from the proximal end of the proximal part 54 (plane 53) of the handle38. Corresponding dimensions LI.2-LI.4, LII.2-LII.4 and LIII.2-LIII.4can be used to indicate the distances of the reference plane 63 fromother minimums that, for example, are associated with the radiiR1.2-R1.4 and R3.1-R3.4 in FIGS. 5 and 6 (for example, see LI.4 andLII.4 in FIG. 6). A dimension LIV.2 indicates, for example, the distanceof the maximum 62 from the reference plane, wherein this distance mayalso be equal to zero, namely if the maximum 62 also lies in thereference plane 63.

[0063] The lengths of the distal and proximal parts 50, 54, as well asof the center part 52, cannot be precisely defined because thisdefinition is arbitrary. For the purpose of the invention, a length L0.1of the center part 52 in the upper section 42 is defined by the turningpoints in which the convex curve section that lies in the xz-plane andcontains the maximum 59 transforms into the adjacent concavely curvedsection that also lies in the xz-plane and contains the minimums 60, 61.In this case, the distal and proximal parts 50, 54 extend from thispoint to the respective end pieces 48, 55. The position of the turningpoints is defined in FIG. 1 by the position of the cross-sectionalplanes 49 and 51 such that the length L0.1 of the center part 52 of thefirst section 42 is equal to the distance between the planes 49, 51. Thesame distance or a different distance can be used for the longitudinaldimension of the center part of the lower section 43.

[0064] In addition, variables A1A-A4A are obtained from FIG. 7 (ifturned to the left in the xy-coordinate system). These variables arereferred to as distance vectors below because they indicate thedistances of the minimums (in this case, for example, 60) from thelongitudinal axis 39. In this case, these distances may be identical toone another or differ from one another. The sum of the dimensions A1Aand A3A results in the height H, and the sum of the dimensions A2A andA4A results in the thickness D of the handle 38, in the sense of thedefinition according to FIG. 2, in the respective cross section A-A.Corresponding distance vectors A1B-A4B and A1C-A4C are obtained for thesectional planes B-B and C-C, wherein the distance vectors A1B and A2Brepresent the most important distance vectors because they define theshape of the handle 38 in the region that contains the curvature 57 andis encompassed by the palm 33 and the fingers that originate at thepalm. The letters A-C, etc., also identify the respective sectionalplanes according to FIGS. 7-9 in this case.

[0065] The previous description indicates that the aforementioned values(for example, R2.1, L0.1, RB.10, A1B, etc.) are all referred to pointsin two selected planes that correspond to longitudinal sections throughthe handle 38 in the xz-plane and the yz-plane The main reason for thiscan be seen in the fact that the point 59, which is of particularimportance for achieving a preferred coupling position and has thegreatest absolute distance from the z-axis, lies, in accordance withthis definition, in the xz-plane. It should be clarified that, inaddition to the longitudinal sections shown in FIG. 5, otherlongitudinal sections or additional longitudinal sections that liebetween the xz-plane and the yz-plane and also contain the z axis can beused for describing the outer surface area of the handle 38. Thisprimarily pertains to the longitudinal sections in the three-dimensionalsector of the upper section 42 that contains the surface area sectionwith the curvature 57 (FIG. 8), and extends over an angular rangebetween approximately 90° and 135° beginning at the yz-plane.

[0066] The arrangement shown represents an optimally designed handle fora right-handed user. An optimally designed handle for a left-handed userwould have a shape that, by comparison to the described handle 38,extends in a laterally reversed fashion referred to the xz-plane. Forright-handed users and left-handed users, the handle would be designedsymmetrically, referred to the xz-plane. This arrangement does notprovide an equally superior contact area for the fingers, as does theasymmetrically designed handle 38. However, the design for right-handedusers already provides left-handed users with a superior contact areafor the hand, by comparison to handles currently available on themarket. If a handle for right-handed users and left-handed users,respectively, should be provided, it may also be practical to arrangeasymmetric sections, in particular, in the region of the distancevectors A2A, A4A, A2B, A4B, etc.

[0067] The handle 38 described above with reference to FIGS. 5-10 iscentered in the hand cavity approximately in the center of itslongitudinal extent. The ball of the hand root and the ball of the handedge respectively contact the upper sections of the distal and theproximal parts. Handles of this type are primarily suitable for lighthammers, small mason's trowels and similar hand and garden tools. Animaginary longitudinal axis of the hand assumes a very steep or nearly aright angle, referred to the longitudinal axis 39 of the respectivehandle 38, in the preferred coupling position. All these handles arerealized in the form of one-piece handles.

[0068] FIGS. 11-13 indicate how the handle 38 is, when using, forexample, a hammer 64, initially taken hold of by the human hand 19, fromthe side of the upper section 42, and subsequently encompassed. FIGS.11-13 show the position for a right-handed user, with FIG. 11 showingthe preferred coupling position of the hand while using the hammer 42. Abroken line 65 indicates the approximate position that the convexcurvature 57 shown in FIG. 8 assumes in the hand 19. FIGS. 12 and 13schematically show two hand positions in the form of sections viewedfrom the distal end, in a position that is, referred to FIG. 8, turnedby approximately 180° about the z-axis, and show the trapezoidal shapeof the index finger joints 23, 24 and 25, shown in FIG. 3, in connectionwith the position of the thumb 20.

[0069] Conventional handles according to the prior art do not fill thecavity of the hand encompassing the handle, and do not sufficientlysupport the hand, such that the muscles of the fingers and the hand arehighly strained. The handle according to the invention is, by contrast,shaped such that a nearly complete support and a very uniform pressuredistribution are achieved, and that the handle “snugly” fits against therespective hand regions at all locations. Practically, the handencompassing the handle should automatically assume a predeterminedcoupling position that is perceived as comfortable and favorable by theuser, and is referred to as the “preferred coupling position” in thiscontext. However, the handles are neither individually adapted to aparticular hand nor designed for an “average hand,” but rather aredimensioned in accordance with “groups of hand sizes” that are obtainedfrom hand measurement data, as well as by sensible sorting andclassification thereof.

[0070] According to the invention, these dimensions and shapes of thehandles are adapted to one another in such a way that the resultinghandle shape and handle size automatically predetermine a preferredcoupling position of the hand for the entire associated group of hands,and that the handle is perceived as lying comfortably in the hand byusers of this group when the respective tool is used, and also whenhigher forces are introduced or when the tool is subjected to use for along duration, due to the uniform pressure distribution. This inventionis, in particular, intended for professional use of the respective toolby craftsmen and causes, if at all, the least possible fatigue and painin the hand or the arm. Among other things, this is achieved due to thefact that, according to FIG. 4, the dimensions L0.1, LI.1, LII.1 andLIII.1 that are shown in this figure and are described above withreference to FIGS. 5 and 6, as well as the corresponding dimensions thatlie in other sectional planes, are essentially realized in accordancewith the shape of the hand. In this case, the dimension L0.1 isessentially defined by turning points in which the concave hand cavitytransforms into the convex curvatures of the thumb bridge 26 on one sideand the ball of the hand edge 31 on the other side. The dimension LI.1is defined by the distance between the center of the hand cavity and thehighest region of the thumb bridge 26, and the dimension LII.1 isdefined by the distance between the center of the hand cavity and thehighest region of the ball of the hand edge 31. The dimension LIII.1 ofthe handle is defined by the distance between the center of the handcavity and the hand edge 30 that needs to be supported on the proximalpart in FIGS. 5-10.

[0071]FIG. 12 shows a highly abstract section through the handle 38 andthe hand 19, of a right-handed user, which encompasses said handle. Thecontact region between the palm 33 and the fingers and the circumferenceof the handle 38 is illustrated in the form of sectors in aleft-rotating angular coordinate system. The angular coordinate plane of0°-180° corresponds to the xz-plane and the angular plane of 90°-270°corresponds to the yz-plane of the Cartesian coordinate system in FIGS.5 and 6. In this case, the longitudinal axis 39, or the z-axis of thehandle 38 according to FIGS. 5 and 6, extends through the point Z.

[0072]FIGS. 12 and 13 also show that the fingers that encompass thehandle 38 laterally and on the underside press in the direction of thepalm 33, as well as in the direction of the inner side of the ball ofthe thumb 28. The balls of the hand edge 31 laterally adjoin theproximal part 54 of the handle 38. The inner side of the ball of thethumb 28 lies approximately along an angular range of 315°-0°, as isschematically illustrated in FIG. 12 by a segment 67 that represents thecontact surface and is illustrated on an excessively large scale. Thepalm 33 adjoins the handle along an angular range of approximately0°-135°, which is indicated in the form of a segment 68, with the middlefinger shown in FIG. 12 adjoining the handle 38 along an angular rangeof 135° up to slightly more than 270° (segment 69) analogously to thering finger and the little finger. For a left-handed user, the angularranges would extend in the opposite direction of rotation.

[0073]FIG. 13 shows that the handle 38 adjoins the inner side of thefingers with its lower section 43 that has a comparatively smallcurvature radius (e.g., RB.12 in FIG. 8), wherein said fingers form anapproximately trapezoidal inner line with their members in theencompassing position. This figure also shows that the thumb 20 adjoins,below its middle joint, one side of the handle 38, and that the indexfinger adjoins the handle 38, on the other side, with its inner sidebelow the first joint. Both fingers laterally exert pressure upon thehandle in the contact regions such that the handle is guided by thefingers. The contact regions subjected to pressure are illustrated inFIG. 13 in the form of hatched segments 70, 71. The thumb bridge 26exerts only a little pressure upon the handle 38, and merely adjoins thehandle with its thin tissue 72 such that no tension in the bridge tissueoccurs. However, this region of the hand is still in adequate contactwith the handle 38. A broken line 73 in FIG. 13 indicates an invisiblepart of the handle 38 within the region of the greatest height andthickness (curvature 57 in FIG. 8).

[0074] Tests on the pressure resistance of the hand surface demonstratedthat a “soft” spot lies in the boundary region between the ball of thethumb 28 and the palm 33. At a uniform specific pressure, this regionwill yield more than the palm 33. Consequently, the curvature 57 (FIG.8) is at its greatest at this point in an ergonomically correct handle,in order to achieve a uniform load distribution over the entire surfaceof the hand curvature.

[0075] According to the invention, the handle shapes and handle sizesare based on the notion that, in particular, the dimensions L0.1, LI.1,LII.1 and LIII.1 according to FIG. 5, and the analogous dimensions inthe other longitudinal sectional planes, are important for achieving anappropriate “fit” and the preferred coupling position. This applies, inparticular, to the contact region of the ball of the thumb 28 and thehand cavity that lies between approximately 315°-135° in the angularcoordinate system according to FIG. 12. This concept is taken intoaccount in the form of the distinct curvature 57 in the center part 52of the upper section 42 of the handle 38 in at least two planes thatextend perpendicular to one another, i.e., in the angular range between0° and 90° referred to FIG. 12. The progression of the curved surfacesof this curvature 57 in the longitudinal direction and thecircumferential direction as they are approximately defined by the radiiRB.10 and RB.11 (FIG. 8) is also important. In addition, the lengths ofthe respective distance vectors beginning at the point Z of therespective cross sections are also important, with the lengths of saiddistance vectors being defined, for example, by the values A1B and A2Bin FIG. 8.

[0076] The radius in the lower section 43 of the handle 38 that isadjoined by the fingers is also important for achieving a comfortablefeel of the handle. The fingers that adjoin the handle and are bent atthe joints form a trapezoidal contour on their inner surface. The radiusor the arc of the handle cross section in this region needs to bedimensioned such that it is tangent to the trapezoidal contour over thelongest distance possible, and the contact pressure is distributed overthe largest possible surface of the fingers. This requirement shouldalso apply if the position of the finger joints changes slightly, forexample, due to changes in the hand position, or with hands that havefingers of different length. The proximal finger joints that adjoin thelower side of the handle form a slightly curved contour that extends inthe transverse direction of the hand when it encompasses the handle.Accordingly, the curvature on the lower side of the handle that isidentified by the radius R2.3 is only slightly curved, i.e., it has alarge radius. The central and distal finger joints adjoin the outer sideof the handle in the region of the lower handle part 43 and part of thecentral handle part 44. The inner contour of these finger joints is alsoslightly curved in the transverse direction of the hand on this side, asindicated by the radius R2.4 in FIG. 6, if the handle has an optimalergonomic design. However, the handles could also be shaped such that acompromise between the optimal design for right-handed users and arelatively adequate shape for left-handed users is achieved. In thiscase, the radius R2.4 is smaller, i.e., the side is curved morestrongly. In any case, the curvature is smaller than the curvature onthe opposite side that is defined by the radius R2.2, and is smallerthan the curvature on the upper side that is defined by the radius R2.1.

[0077] For the purpose of the invention, existing anthropometricinvestigations, as they are published on page 231 of Research Report 156by the German Federal Institute for Occupational Safety and AccidentResearch of 1979, were used as the basis for deriving the dimensions L0,LI, LII and LIII. Initially, three groups of hand sizes were specified:“S”=“small,”“M”=“medium” and “L”=“large.” Hand sizes up to the 20thpercentile were categorized as “small,” hand sizes between the 20th andthe 75th percentile were categorized as “medium,” and hand sizes up tothe 100th percentile were categorized as “large.” According to theinvention, it was determined that the dimension L0.1 according to FIG. 5should approximately amount to 50%, preferably 45%-55%, of the averagehand width according to dimension B in FIG. 3. In addition, thedimension LII.1 according to FIG. 5 should approximately amount to33%-37% of the average hand width B and the dimension LIII.1 shouldapproximately amount to 50%-55% of the average hand width B. Thisresults in a LIII.1 value of approximately 47 mm-60 mm for the handsizes “S” through “L.” If this is weighted with the hand widths found inthe cited investigation, the length L0.1 amounts to approximately 43 mmfor small hands (S), approximately 46 mm for average hands (M), andapproximately 48 mm for large hands (L). Based on these coremeasurements, the remaining measurements of the handles were determinedempirically based on models and group tests, wherein the desire forstandardization was also taken into account. Different finger lengths asthey were found on hands of identical width were consequently not takeninto consideration in the design and the dimensions of the handles.

[0078] The handle size essentially is adapted to the various hand sizeswithin the dimensional ranges LI and LII, wherein the total length ofthe handles preferably remains the same. The distal and the proximal endpieces 48, 55 are adapted in the form of continuous progressions thatextend up to the handle ends in the cross sections occurring in the endpoints of the handle 38. In handles that contain a thumb support in thedistal region, the total length of the handle is preferably also changedin order to adapt the handle to the hand size.

[0079] Surprisingly, it was determined that handles with theabove-described characteristics and dimensions are suitable for varioustools. Depending on the respective function, only comparatively slightchanges in the basic shapes are required. This means that at least thecenter parts 52 of the upper sections 42 are realized very similarlywith respect to their size and shape. Depending on the intended use ofthe respective tool, different shapes are, in particular, practical inthe region of the distal end pieces 48 of the handles 38. In certainrespects, this also applies to the proximal end pieces 55. Depending onthe type and size of the tool on which the handles 38 are used, it ispractical to vary the height H and the thickness D or the length of thedistance vectors. However, the contour that adjoins the hand is verysimilar in handles 38 that are used for various tools.

[0080] In order to achieve a superior fit of the handle 38 in the handcavity or a shape that is largely adapted to the hand cavity, the parts50, 52 and 54 in the upper section 42 are, according to the invention,considered to be particularly important as described explicitly withreference to FIGS. 11-13 (the adjacent sides of the section 44 are alsoconsidered to be important, but this section is omitted in this casebecause the entire upper part of the handle is assigned to the section42 and the entire lower part of the handle is assigned to the section43). Consequently, the shapes and dimensions are adapted at theselocations in such a way that the preferred coupling position is assumedalmost automatically by all hands of the respective group of hands, duepractically only to the upper section 42.

[0081] The surfaces of the inner section 44 (FIG. 8) of the handle 38are also curved convexly outward in this embodiment (FIGS. 7-10) inorder also to provide a superior support surface for the hand in thisregion. In addition, the surfaces of the sections 42 and 43 are realizedcontinuously, i.e., the transitions between the various surfaces of thesections 42, 43 and 44 are preferably continuous and smooth, such thatthe convexly curved center part 52 gradually transforms into the parts50 and 54 that are curved concavely inward.

[0082] In this embodiment, the lower section 43, which is situateddiametrically opposite to the upper section 42 and lies below animaginary central plane (=yz-plane) of the handle 38 in FIG. 5, isshaped and dimensioned similarly to the upper section 42. This lowersection is rounded, in particular, in the shape of an egg, and containsno corners or edges that press against the fingers (FIGS. 7-10).

[0083] In order that the preferred coupling position of the hands of anassociated group of hands is not only automatically assumed, butpractically becomes mandatory due to the design of the handle, selecteddimensions of the handle 38 can be further defined based on experienceand investigations as deemed practical for a coupling position, inparticular when handling a hammer. For example, the parts 50 and 54 mayascend less concavely than in FIG. 5 from the minimums 60, 61 (FIG. 5)in the proximal and in the distal direction, or even be flat or plane.In this case, the minimums 60, 61 are those points that have thegreatest distance from a chord drawn through the end points of the parts50 and 54. However, a continuously concave progression of the parts 50and 54 and the corresponding parts in the remaining handle sectionsprovides the significant advantage that the handle 38 fits the hand inan almost positive fashion, such that its tendency to slide in thedirection of the longitudinal axis 39 is reduced when using the tool.

[0084] Other important dimensions for the purpose of the invention arethe curvature radii, in particular, the radius R2.1 and R2.2 (FIG. 5)which, depending on the hand size, lies between 50 mm and 120 mm. Thesedimensions essentially define the convex curvature in the longitudinaldirection. Another important dimension is the radius R22 in theyz-plane. This radius defines part of the longitudinally extendingcurvature in the second direction. This applies analogously to thelongitudinally extending radii in the transitions between the xz-planeand the yz-plane, for example, the radius R2.5.

[0085] Other important dimensions are the radii RA.10-RA.13, RB.10-RB.13etc. and, in particular, the radius RB.10 and RB.11. This radius definesthe progression of the curvature 57 (FIG. 8) in a second direction(y-axis and yz-plane, respectively) such that the curvature 57 ispronounced in two directions that extend perpendicular to one another.In a handle 38 for left-handed users, the radius RB.13 would have to bedimensioned accordingly in order to make the curvature more distinctlypronounced toward the right side in FIG. 8.

[0086] In addition, the total thickness D and the total height H of thehandle 38 are naturally important in this context. FIGS. 7-9 indicatethat the distance vectors A1A-A4A, A1B-A4B etc. may respectively beidentical or different in the x-direction and the y-direction.

[0087] In handles 38 that are realized symmetrically referred to thexz-plane and/or the xy-plane, the corresponding values A1A-A4C may beidentical (e.g., A1B=A3B and/or A2B=A4B), and can consequently bereplaced with the dimensions H and D. It is also preferred topredetermine identical values at least for the dimensions L0.1 of thehandles for a preselected group of hands, with the dimensions R2.1 lyingclose to one another. It is preferred to carry out a weighting in such away that, for example, the different dimensions of the distal part 50are defined in order to realize the preferred coupling position inaccordance with the above-described dimensions, with the dimensions ofthe proximal part 54 and, if applicable, the proximal end piece 55 beingof lesser importance in this case.

[0088] With respect to the dimensions LI.1 and LII.1, it may beadvantageous to choose approximately identical values for thesedimensions for most handles, i.e., the maximums 59 are arranged in thexz-plane in the center between the corresponding minimums 60 and 61.However, there may also be instances in which the maximums 59 are notarranged exactly in the center, but rather are offset toward the distalend or the proximal end. In addition, the distal and proximal parts 50,54 of the handles 38 usually have approximately the same length so thatthe center parts 52 lie essentially in the center between the twoadjacent distal and proximal parts 50, 54.

[0089] It is also important for the invention to standardize a series ofthe above-described dimensions R, L, A, H and D, and to predetermineessentially identical values for a series of hand and garden tools. Thisis based on the idea that handles of the described type are realizedvery similarly with respect to size and shape, not only in the centralpart 52, but also the distal part 50. In such instances, it is merelyrequired to adapt a few of the indicated dimensions, e.g., the distancevectors, as well as the proximal parts 54 and/or the proximal end pieces55, to the given application (tool type) with respect to their size andshape. This provides the user, particularly the professional user, withthe advantage that various types of tools will have handles of the samebasic size and shape, so that the user will easily be able to selectsuitably fitting handles.

[0090] On the distal and/or proximal end of the handle 38, the endpieces 48 and/or 55 are preferably designed in the form of a bulge. Thisis realized by dimensioning their cross sections to be greater than inthe region of the sections A-A and C-C in FIGS. 7 and 9. In thepreferred coupling position of the hand, the outer sides of the fingerjoints of the index finger and the little finger and, if applicable, thehand edge 30 and the ball of the hand edge 31 are supported on these endpieces 48, 55.

[0091] According to FIGS. 6 and 10, the handle 38 may also be providedwith a support surface 74 for the thumb 20. This support surface 74preferably lies on the upper side of the distal end piece 48 and aregion of the distal part 50 situated adjacent thereto. FIG. 10, inparticular, shows that this support surface may consist of a trough orflattening that extends parallel or slightly oblique relative to theyz-axis.

[0092] Another preferred embodiment of a handle 78 is shown in FIGS.14-18. This handle 78 essentially differs from the handle 38 only inthat a support surface 80 is arranged on the surface of the center part79. Specifically, the cross section in FIG. 17 indicates that thissupport surface is arranged on the side of the xz-plane which faces awayfrom a curvature 81, wherein the curvature 81 corresponds to thecurvature 57 in FIG. 8. According to FIGS. 14 and 15, the supportsurface 80 may also extend over a larger region or even the entireregion of the center part 79 in the direction of the longitudinal axis82 of the handle 78. In other respects, the support surface 80, like thesupport surface 83 for the thumb, is essentially realized to be flat orslightly concave, i.e., in the form of a groove or trough that extendsin the direction of the longitudinal axis 82. This support surface isprovided in addition to or instead of the support surface 83. Thesupport surface 80 advantageously serves for supporting the ball of thethumb 28 in order to achieve an even better adaptation to the hand andan even more comfortable coupling position.

[0093] The most important dimensions for a preferred embodiment of thehandle 78 according to the invention are indicated in the tables shownin FIGS. 93a and 93 b. The dimensions listed in these tables indicate intwo columns [sic] the dimensions specified for a given group of small,medium and large hands. The dimensions for a medium hand “M” fallbetween the values for “S” and “L,” wherein intermediate sizes may alsobe provided if so required. According to the invention, a total of threegroups, namely, “small,” “medium” and “large,” is considered sufficient.A more detailed explanation of FIGS. 93a and 93 b is provided below.

[0094] In the embodiment according to FIGS. 19-24, the handle 86 isintended for a tool in the form of a mason's trowel, which is notillustrated in these figures. The handle 86 essentially corresponds tothe handle 38 according to FIGS. 5-10, where said handle a supportsurface 87 for the thumb, as in FIGS. 6 and 10. A distal handle end liesin a plane 89 that extends perpendicular to a longitudinal axis 88 ofthe handle 86, with the distal end piece 90 ending in the aforementionedplane. As in the previous description, one respective distal part 91,one center part 92, one proximal part 93 and one proximal end piece 94are situated adjacent to this end piece 90.

[0095] The values for the various dimensions are chosen so that thehandle 86 is also suitable for other tools besides mason's trowels,e.g., heavy hammers, roofing hammers, sledge hammers, axes and, in ananalogous two-part design, for garden and pruning shears. The importantdimensions for a preferred embodiment of the handle 86 are indicated inthe tables according to FIGS. 94a and 94 b. This applies, in particular,to the length L0.1 of the center part 92 arranged between the twocross-sectional planes 95, 96 which is measured in an upper section andapproximately corresponds to 50% of the hand width of the assigned groupof hands, as well as to the dimensions LI.1 and LII.1 that define theposition of the minimums 97, 98 of the upper surface contour in thedistal and the proximal part 91 and 93. The position of a referenceplane 95 is defined by the maximum 100 of the center part 92 in FIG. 5.In other respects, the handle is designed essentially identically to thehandle according to FIGS. 5-10.

[0096] FIGS. 25-30 show a second embodiment of the handle 86 accordingto FIGS. 19-24, wherein the same reference symbols were used fordesignating identical components. In addition to the support surface 87provided on the upper side of the upper section, a second lateralsupport surface 101 for the thumb 20 is provided in this case. Thissecond support surface lies in the distal part 91 of the handle 86analogous to the support surface 87 and preferably extends into thedistal end piece 90. The cross sections in FIGS. 27 and 30, inparticular, indicate that the support surface 101 is arranged on theside of the xz-plane which faces away from the curvature 102, where saidcurvature 102 corresponds to the curvature 57 in FIG. 8. The supportsurfaces 87 and 101 may essentially be realized flat or slightly concaveso that they are adapted to the shape of the thumb. FIGS. 27 and 29 showthat the support surface 101 may extend from an upper section 103 of thehandle 86 into an adjacent inner or central section 104 that can also beassumed to be omitted in its entirety. The lateral support surfaceserves for achieving an additional lateral guidance of the handle. Asimilar lateral support surface may also be provided on the handles forhammers which are shown in FIGS. 5-6 and FIGS. 10-18. In other respects,the handle is designed essentially identically to the handle accordingto FIGS. 19-24.

[0097]FIG. 31 shows the handle 86 in connection with a mason's trowel105, namely in the position in which it is grasped by the hand 19 of aright-handed user in a first preferred coupling position. In this case,the thumb 20 rests on the upper support surface 87. FIG. 32, incontrast, shows the handle 86 of the mason's trowel 105 in the positionin which it is held by a right-handed user in a second preferredcoupling position. In this case, the thumb 20 adjoins the lateralsupport surface 101, which is not visible in FIG. 32.

[0098] The handles 38, 78 and 86 according to FIGS. 5-32 areparticularly suitable for tools 64, 103 in which the hand encloses thehandle from the top in the preferred coupling position. FIGS. 33-37 showa handle 106 for a tool that is pushed and pulled, i.e., a saw 107 or,for example, a hand plane, a firmer chisel (wood chisel) or the like.According to FIGS. 33-37, the handle 106 of the saw 107 is mounted on afunctional part 108 by means of screws or the like. The handle 106 isprovided with a central opening 109 as is customary, for example, withstraight-back handsaws with open handles. This handle is provided withan upper section 110 (on the right in FIG. 36) that contains supportsurfaces for the inner side of the hand on the side of the handle 106which faces away from the functional part 108 or the opening 109, namelyanalogous to FIGS. 1, 2 and 5-32. A lower section 111 of the handle 106(on the left in FIG. 36) which faces the opening 109 is provided withsupport surfaces for the fingers. The sections 110, 111 and a section112 (FIG. 17) situated between the two aforementioned sectionscorrespond to the sections 7, 8 and 9 in FIGS. 1 and 2. A handle for abow saw or the like may be realized accordingly.

[0099] A comparison between FIGS. 5-9 and FIGS. 33-37 shows that thesurface contours of the sections 110, 111, as well as of the innersection 112 (FIG. 36) that connects the two aforementioned sections, arerealized largely identically to the sections 42-44. In addition, thehandles 38, 78, and 86 each comprise a distal end piece 114, a distalpart 115, a center part 116, a proximal part 117, and the proximal endpiece 118, which are arranged one behind the other in the direction ofthe longitudinal axis 119 (FIG. 34), analogously to the handle 106. Thecross-sectional plane B-B which extends through a summit or maximum 120of the surface contour of the center part 116 in the upper section 110again serves as the reference plane. The length of the convex centerpart 116 is defined by the position of the turning points to theadjacent concave parts 115, 117 and by cross-sectional planes 121, 122that extend through these turning points, with the length of the convexcenter part being dimensioned at approximately 50% of the hand width B(FIG. 3) of the average user of the assigned group. The position ofconcave minimums 123, 124 of the distal and the proximal part 115, 117is respectively defined by the dimensions LI.1 and LII. 1, with thevalues of these dimensions being identical to those in FIGS. 5-10.

[0100] In other respects, the previous explanations regarding thehandles 38, 78, and 86 also apply in this case, with the variousdimensions being indicated in the tables according to FIGS. 95a and 95b. In addition, FIGS. 38 and 39 indicate how the handle 106 is initiallytaken hold of from the rear and then enclosed with the human hand 19while the saw 107 is used. The position for a right-handed user isillustrated in FIGS. 38, 39, with this position simultaneouslyrepresenting the preferred coupling position of the hand while using thesaw 107.

[0101] The handles 38, 78, 86 and 106 described thus far are explainedin greater detail by means of side views and top views, as well as a fewcross sections that extend perpendicular to their longitudinal axes(e.g., FIGS. 27-30). In this case, the side views and top viewsrespectively show an outer contour in the upper end of the lower regionwhich has the shape of a concave-convex-concave curve 127, 128 (FIG. 25)and 129, 130 (FIGS. 26). This outer contour would also result if alongitudinal section that contains the z-axis and lies in the xz-planewould be illustrated in FIG. 25 instead of the side view shown, and if acorresponding longitudinal section that lies in the yz-plane would beillustrated in FIG. 26. Consequently, each of these curves 127-130represents a (usually different) generatrix of the surface area of thehandle body, wherein the handle body would represent a body ofrevolution with the z-axis as the axis of rotation if all curves 127-130were identical. For example, FIGS. 25 and 26 show that one particularityof the invention can be seen in the fact that the curves 127-130 mayhave entirely different progressions because the handles designed inaccordance with ergonomic requirements largely have an asymmetric shape.

[0102] In the previous description, it was assumed that the crosssections, e.g., according to FIGS. 27-30, are essentially egg-shaped oroval or elliptical, except for possibly provided support surfaces 87, 99in order to simplify the illustrations. In this case, the respectivelylargest diameter lies, according to FIGS. 1 and 2, on a line thatextends parallel to the x-axis, with the respectively smallest diameterlying on a line that extends parallel to the y-axis. Consequently, thedescribed maximums and minimums (e.g., 97, 98, 100 and FIG. 25) lie inthe xz-plane. This means that the curve 127 extends in one plane. Thisapplies accordingly to the curves 128-130, wherein the curves 129, 130lie, however, in the yz-plane. In addition, it was assumed in theprevious description that the maximums (e.g., 100 in FIG. 25, but also59 and 120 in FIGS. 5 and 33) define the point on the surface area ofthe handle body which has the greatest absolute distance from therespective z-axis (e.g., the dimension A1B in FIG. 22). This is thereason the curve 127 represents the geometric locus of all points on thesurface area of the handle body which respectively are the greatestdistance from the z-axis along the latter, and thus forms a generatrixof the surface area which always has a convex progression in the regionof the curvature 102 and, according to the invention, respectively liesin the upper section 42 or 102.

[0103] Except for the position of the curvature 102 in the upper section42 or 102, these prerequisites are neither absolutely imperative noralways advantageous with respect to ergonomic aspects. It may, inparticular, be practical to shift the point that has the greatestdistance from the z-axis into a plane which is arranged parallel to thexz-plane that always represents the central plane in this case. This,among other things, makes it possible to achieve an improved adaptationof the handle 86 to the cavity of the hand 19, in particular, due to amore pronounced lateral excursion of the curve 102 (FIG. 28). Forreasons of simplicity, it may also be specified in this case that thecurve containing the absolute maximum represents a curve that lies in aplane that extends parallel to the xz-plane. It would, in contrast, alsobe possible for the curve containing the absolute maximum to representthe geometric locus of all points that are the greatest distance fromthe z-axis along the latter. This means that this curve may alsorepresent a three-dimensional curve that only lies on one side of thexz-plane or contains points that lie on both sides of this plane. Thisis described in greater detail below with reference to FIGS. 40-45.

[0104] FIGS. 40-43 show longitudinal sections through a handle 131, theouter contour of which essentially corresponds to the previousdescription. FIG. 40 shows a longitudinal section in the xz-plane whichcontains the z-axis such that the contours essentially correspond, forexample, to those in FIG. 19 and/or 25. FIG. 41 also shows alongitudinal section that contains the z-axis, but this longitudinalsection corresponds to a sectional plane that extends from 45° to 225°in the angular coordinate system shown in FIG. 12. FIG. 42 shows alongitudinal section in the 90°-270° position according to FIG. 12, andFIG. 43 shows a longitudinal section that contains the z-axis,analogously to the remaining longitudinal sections and extends from 135°to 315° in FIG. 12. The three longitudinal sections shown in FIGS. 41-43can also be assumed to be generated by incrementally turning the handle131 by 45°, starting from the position shown in FIG. 40 and thensectioning the handle parallel to the plane of projection.

[0105]FIG. 44, based on FIG. 40, shows a total of 20 cross sections thatextend perpendicular to the z-axis. This means that the x-axis of theimaginary coordinate system points vertically upward in all sections. Ifall sections shown in FIG. 44 are arranged one behind the other on thez-axis at the distances indicated in FIG. 40, their circumferentiallines 132 (see cross section A in FIG. 44a) very closely represent thesurface contour of the complete surface area of the handle 131 whenconnecting all circumferential lines 132 to one another over theshortest possible distance by means of conical surfaces. The accuracy ofthe thereby obtained surface area is improved as the number of crosssections used increases.

[0106] According to the present invention, it is important that theupper section that contains the curvature and that is identified byreference symbol 103, analogously to FIG. 28 (see cross section A inFIG. 44a), contain not only points that lie in the xz-plane but alsopoints 133-143 that are the greatest distance from the z-axis in therespective cross section and at least partially do not lie in thexz-plane. The distance vectors 144-154 which lead to these points133-143 are respectively indicated in FIGS. 44a and 44 b in the form ofarrows. This indicates that the radius vectors 144-154 partially extendon the right side of the xz-plane and partially on the left side of thisplane similar to spatial vectors. In this case, the angles a (see crosssection H) formed in connection with the xz-plane precisely indicate inwhich longitudinal sectional plane that is formed as in FIGS. 40-43 andincludes the z-axis the points 133-143 lie. Here, all points 133-143theoretically may lie on different longitudinal sections.

[0107] The radius vector 147 in the cross section K has the absolutegreatest length of all radius vectors that are shown in FIG. 44 and thatlie within the region assigned to the central part (see, for example,the cross sections H-R). Consequently, the point 136 defined by thisradius vector has the greatest distance from the z-axis within thecentral part in the upper handle section, with this point corresponding,for example, to the maximum 100 in the illustration of FIG. 25. Inaddition, FIG. 45 shows that the points 133-143 which are connected bythe curves 155 and 156 have partially positive and negative y-values inthe xyz-coordinate system shown in FIG. 12. However, all x-values arepositive and have their minimum in the cross section L such that theylie on a three-dimensional curve.

[0108] In contrast to FIGS. 40-44, it is also possible to locate thepoints 133-143 so that they all lie on the same side of the xz-plane,but at a certain distance from this plane. The shape selected for anindividual instance largely depends on the location at which thedifferent maxima and curvatures lie and how pronounced these maxima andcurvatures should be.

[0109] With respect to the dimensions L0.1, LI.1, LII.1 and LIII.1 thatwere described with reference to FIG. 5, only a few modifications weremade in the arrangement according to FIGS. 40-45. If the points thathave the greatest distances from the z-axis lie on a curve that islocated in a plane that includes the z-axis, the xyz-coordinate systemis simply turned about the z-axis by such an angle that the xz-planecorresponds to the plane containing the plane curve. The new coordinatesystem obtained thereby is then used for defining the various dimensionsanalogous to the previously described coordinate system, with areference plane that corresponds to the reference plane 63 (FIG. 5) andis arranged perpendicular to the z-axis being located, in particular,through the point with the greatest absolute distance from the z-axis.Consequently, the only difference can be seen in the fact that the newxyz-coordinate system assumes a different position in space than thecoordinate system in FIG. 5.

[0110] If the points 133-143 in FIGS. 44 and 45 would lie in one planeand this plane would not contain the z-axis, but is, for example,arranged parallel to the xz-plane, the coordinate system according tothe previous description may be turned in a such a way that the point136 with the greatest absolute distance from the z-axis lies in theturned xz-plane. When using the aforementioned definitions for thedimensions L0.1, LI.1, LII.1, LIII.1 etc., slightly different valuesthan those determined in the plane that contains all points 133-143would be obtained. This applies correspondingly if the points 133-143 donot lie on a plane curve, but rather on a three-dimensional curveanalogous to FIGS. 44, 45, and if a plane that contains the z-axis andthe point 136 is used as the new xz-plane. In such instances, thepositions of the maxima and minima determined in accordance with FIGS.5-10 and the values for the dimensions L, R, A etc. slightly deviatefrom the actual values. However, the deviations become smaller as thedistance of the maximum 136 from the xz-plane decreases (see, forexample, FIG. 45) such that the definitions outlined above withreference to FIGS. 5-10 can be used here for achieving a superiorapproximation. This is the reason the, value ranges indicated in thetables according to FIG. 93a-FIG. 96c also include handles in which themaximum (e.g., 59 in FIG. 5) lies on a three-dimensional curve and/ornot in the described xz-plane. In other respects, the cross section K inFIG. 44a schematically indicates in which sectional planes of thelongitudinal sections according to FIGS. 40-43 appear. In this case, alongitudinal section L1 is referred to as a section in the xz-plane(α=0°), and a longitudinal section L2 is referred to as a section in theyz-plane (α=90°). Accordingly, L3, L4 and L5 refer to longitudinalsections with the angles α=180°, α=270° and α=45° which include thez-axis, namely viewed in the directions of the respective arrows. Theselongitudinal sections L1-L5 are also indicated in the table.

[0111] The tables according to FIGS. 94a, 94 b contain numerical valuesin millimeters for a handle that is designed in accordance with FIGS.40-45 and FIGS. 19-24, wherein the longitudinal sections L1-L5 in column1 of FIG. 94a correspond to the longitudinal sections at angles of 0°,90°, 180°, 270° and 45° in accordance with the representation in sectionK of FIG. 44. Column 2 contains the three selected groups of hands,column 3 contains the corresponding hand widths B, and column 4 containsthe handle lengths, for example, between the planes 45 and 46 in FIG. 5.The lengths and radii according to the definitions indicated in FIG. 5are contained in columns L0-LIII and R1-R3, wherein, for example, thedimension of 41 mm (handle size “M”) that is formed by the combinationof L2 (column 1) and LII (column 7) means that this length LII iscontained in the longitudinal sectional plane L2 and corresponds to thedimension LII.2 in FIG. 5, although in the corresponding sectionalplane. In this case, the value formed from L1 and LII corresponds to thevalue LII.1 drawn in the xz-plane in FIG. 5. This means that allimportant dimensions for the handle according to FIGS. 40-45 can beobtained from the tables. Accordingly, the dimension R2 (next to thelast column in FIG. 94a) indicates, for example, in connection with L2that this pertains to the radius R2.2 in FIG. 5.

[0112] Corresponding dimensions for the radii R10-R13 are indicated inFIG. 94b, wherein R10 in column K corresponds, for example, to theradius RB.10 in FIG. 8 because it lies at the maximum (see cross sectionK in FIG. 44a). Accordingly, the dimension A2 in the sectional plane Krepresents the dimension A2B in FIG. 8.

[0113] FIGS. 46-50 show grid representations of a handle 157 in whichthe points with the greatest distance from the z-axis lie on athree-dimensional curve that extends in the longitudinal direction ofthe handle 157 analogous to FIGS. 40-44. In this case, the distal end isrespectively arranged on the left and the proximal end is respectivelyarranged on the right. The handle 157 in FIG. 46 is illustrated in theform of a perspective presentation, with FIG. 47 showing a side viewanalogous to the illustrations in FIGS. 5, 14 and 19, namely a view fromthe right side—looking from the distal end—of the handle 157. FIG. 48shows a top view, FIG. 49 shows a side view from the opposite side, andFIG. 50 shows a bottom view of the handle, with these views resulting byrespectively turning the handle 157 90° about a longitudinal axis 158starting with FIG. 47. In the preferred instance, the left side againrepresents the side that is provided with a pronounced curvature 159that extends in at least two directions.

[0114] The handles (e.g., 38) described thus far are respectivelyrealized in one piece, wherein the first sections (e.g., 42) areintegrally connected to the second sections (e.g., 43) by means ofadapted inner sections (e.g., 44). However, the invention is not limitedto handles of this type, but may be analogously realized in two-parthandles with arms that can be moved relative to one another, e.g.,handles for pliers, scissors or the like. As in FIGS. 1 and 2, in thefollowing description, one of the two handle arms is referred to as thefirst section and the other as the second section, with the two arms orsections being separated from one another by an intermediate space, incontrast, for example, to FIGS. 5-10, so that the two arms or sectionsare not physically connected to one another.

[0115] When designing handles for pliers, it is important that all fourdistal finger joints 25 (FIG. 3) adjoin the surface of the second, lowersection as uniformly as possible when the pliers are in the openposition, e.g., before cutting a wire or before surrounding an objectwith the serrated jaws of universal pliers, in order to be able to exerta sufficient force. However, the surfaces of this section should adjointhe central finger joints 23 when the pliers are closed.

[0116] FIGS. 51-55 show a handle 160 according to the invention, which,for example, is intended for adjustable gripping pliers. In this case, ahandle arm or upper section 162 is realized analogously to the first orupper section of the handles described thus far (e.g., 42 of 38) on itsouter surface, with the other handle arm or lower section 163 beingrealized analogously to the second or lower section of the handlesdescribed thus far (e.g., 43 of 38) on its other surface. The twosections 162 and 163 are realized on both sides of a central plane(yz-plane) that extends through a longitudinal axis 164. In order tomake it possible to selectively use the pliers in two positions that areturned about the longitudinal axis 164 by 180° and to achieveapproximately the same preferred coupling position relative to the handcavity and the ball of the thumb, the lower side of the lower section163 in FIG. 51 is realized with the same shape as the upper side of theupper section 162, but in a laterally reversed fashion relative to acentral plane (xy-plane). Thus, the underside of the section 163 or 162which respectively lies on the bottom when the given tool is used doesnot provide optimal contact surface for the fingers. Since the uppersides of both sections 162, 163 which are of particular importance forthe invention have identical shapes, only the design of the uppersection 162 in accordance with the invention is described in greaterdetail below. In this case, the central plane is preferably placed sothat it contains a not-shown rotational axis that connects the two armsof the pliers to one another, with this rotational axis extendingperpendicular to plane of projection in FIG. 51 and consequentlyparallel to the y-axis in the sense of the definitions used thus far.

[0117] According to FIGS. 51 and 52, the upper section 162 is providedwith a surface contour 165 and is divided into a distal part 168, acentral part 169 and a proximal part 170 that are arranged one behindthe other in the longitudinal direction by means of imaginary planes166, 167. According to the invention, the section 162 is shaped anddimensioned in such a way that the central part 169 is situated in thehand cavity in the conventional coupling position of the hand foruniversal pliers, with the distal part 168 being encompassed by thethumb bridge 26 and the proximal part 170 serving as a contact surfacefor the ball of the hand root 29 and the ball of the hand edge 31.Consequently, the central part 169 has a pronounced convex curvature 171that is directed outward in the longitudinal direction and in thetransverse direction, wherein the distal part 168 is tapered beginningat the center part 169 and continuing to a collar 172 that prevents thehand from sliding off the handle and is arranged on the distal end. Theouter contour of the distal part 168 is realized in a lateral region 174in such a way that it extends with a flat concave arc and with a slightangle of inclination relative to the longitudinal axis 164 in the sideview shown in FIG. 52, with said contour also extending in slightlyconcave fashion along the upper surface 165 shown in FIG. 51, but with acomparatively large angle of inclination relative to the longitudinalaxis 164. Similarly, the proximal part 170 extends on the upper surface(FIG. 51) at a comparatively large angle of inclination relative to thelongitudinal axis 164, but in essentially concave fashion. In a lateralregion 175 (FIG. 52), its surface extends at a comparatively small angleof inclination relative to the longitudinal axis 164 and essentially inslightly descending concave fashion to the proximal end. On the proximalend, the upper section 162 is preferably hemispherical.

[0118] In other respects, the outer contour of the section 162 isdimensioned and shaped in the longitudinal section and in the crosssection, as well as in the direction of the handle height H and in thedirection of the handle thickness D, such that the other section 163, ifrealized identically, is sufficiently well adapted to the trapezoidalinner contours of the enclosing fingers in the preferred couplingposition. In this case, the curvature 171 in the section 162 is realizedin accordance with a curvature 176 in the section 163 that becomeseffective after the pliers are turned by 180° about the longitudinalaxis 164.

[0119] Surfaces 162 a, 163 a of the sections 162, 163 which face oneanother are not important for the purpose of the invention, andconsequently may be conventionally designed with rounded edges. Thehandle height H at the different locations along the handle 160 (FIGS.53-55) and, in particular, the curvatures were dimensioned in accordancewith the assigned group of hands such that a comfortable preferredcoupling position is achieved while taking into account the function ofpliers.

[0120]FIG. 56 indicates how the handle 160 is encompassed by the humanhand 19 when the pliers are used. This figure shows the conventionalposition for right-handed users, with FIG. 56 showing the initialprocess of taking hold of the pliers from the rear, FIG. 57 showing thepliers being used in connection with the preferred coupling position ofthe hand, and FIG. 58 indicating in a section like FIG. 13 how the twosections 162, 163 of the handle 160 are separated from one another andarranged on both sides of the xy-plane in the preferred couplingposition of the hand 19. The broken line 177 in FIGS. 56 and 57 alsoindicates where the curvatures 171 and 176 shown in FIG. 54 areultimately located on the hand 19.

[0121] Analogous to the handle 38, the cross-sectional plane B-B in amaximum 178 in the upper section 162 serves as the reference plane forthe handle 160, with said maximum lying in a plane that extends parallelto the xy-plane on one hand and in a longitudinal section that lies inthe xz-plane on the other hand.

[0122] The length L0.1 of the convex center part 169 is defined by theposition of the turning points to the concave adjacent parts 168, 170and by the cross-sectional planes 166, 167 that extend through theseturning points, respectively. Analogous to one-piece handles, thislength amounts to approximately 50%, preferably 45%-55%, of the handwidth B (FIG. 3) of the average user of the assigned group. The positionof concave minimums 179, 180 of the distal and the proximal part 168,170 is defined by the dimensions LI.1 and LII.1, wherein thesedimensions may have the same values as those in FIGS. 5-10.

[0123] In other respects, the same explanations as those that refer tothe handle 38 apply, with the various dimensions being indicated in thetables according to FIGS. 96a, 96 b.

[0124] In an embodiment of the pliers handles 183 which are illustratedin FIGS. 59-63, the upper section and the lower section 184, 185 are,relative to the surfaces that come in contact with the hand cavity andthe ball of the thumb in the preferred coupling position, also realizedasymmetrically, e.g., in accordance with FIGS. 61-63. In particular, thelower surface of the section 185 intended for contact by the fingers isrealized in a largely cylindrical fashion, when seen in cross section.However, this lower surface only has a slight curvature in the directionof a longitudinal axis 186 (see R2.2 in FIG. 59). In this case, theradii and the other dimensions in the lower section 185 are chosen sothat this section provides a very comfortable contact surface for thefingers that enclose this section. The “trapezoid” (see also FIG. 58)formed by the bent finger joints 23-25 (FIG. 3) and the thumb 20consequently is practically filled by the handle 183 such that a veryuniform pressure distribution is possible. The upper section 184 isrealized in accordance with the upper section of the handle 160 in FIGS.51-55.

[0125] The pliers illustrated in FIGS. 51-63 contain handles 160, 183for the right-handed user. If the corresponding handles are designed forthe left-handed user, the sections 162, 163 and 184, 185 are realized ina laterally reversed fashion relative to the xz-plane (see 61-63).

[0126] In other respects, the previous explanations with respect to thehandle 160 apply.

[0127]FIGS. 64 and 65 show a handle 189 that contains two sections 190,191 that are realized in a laterally reversed symmetrical fashion oneither side of the longitudinal axis 192 and a central plane (yz-plane)containing this longitudinal axis. Both sections 190, 191 have a clearlypronounced curvature 194 in the sense of the other described handles ina central part 193, namely in the x-direction and in the y-direction.Such a handle shape provides optimal properties for right-handed andleft-handed users in the upper section 190 (or 191) that cooperates withthe hand cavity. In addition, the handles 189 are significantly improvedin comparison to pliers handles available on the market within thesection 191 (or 190) that is enclosed with the fingers.

[0128] Most known pliers handles, namely also handles for largeruniversal pliers or cutting pliers, are simply not sufficientlyergonomic because they do not contain a proximal part with superiorergonomic design or suitable contact surface for the ball of the handedge. Even the pliers handles of larger pliers are too short or extendup to the proximal end in the form of a continuous arc that lies in oneplane such that they are by no means adapted to the hand cavity. Theentire compressive force consequently must be exerted by the handcavity. In order to reduce the specific pressure in this region, theinvention proposes to extend at least the handles of larger pliers tosuch a degree that the ball of the hand edge also adjoins acorresponding proximal part (e.g., 170 in FIG. 51). Thus, thecompressive forces exerted by the ball of the hand edge are providedwith a longer lever arm such that the compressive forces acting upon theinner surfaces of the hand are additionally reduced. Consequently, theconcave-convex-concave surface contour explicitly described above isalso effectively realized in pliers handles.

[0129] Naturally, other types of pliers, e.g., wire strippers, universalpliers, needle-nose pliers and other gripping and cutting pliers, aswell as shears, in particular, plate shears, may be equipped with thedescribed pliers handles and other pliers handles.

[0130] Like FIGS. 40-50, FIGS. 66-74 show longitudinal sections, crosssections and grid or dot matrix representations of a hammer handle,e.g., a hammer handle according to FIGS. 14-18. In this case,longitudinal sections are also illustrated in the four planes 0°, 45°,90° and 135° (FIGS. 66-69), with FIG. 70 containing a series of crosssections A-L along the z-axis. Practical dimensions for such a sectionare indicated in the tables according to FIGS. 93a, 93 b which arestructured analogously to the tables according to FIGS. 94a, 94 b.

[0131] FIGS. 75-83 show representations that correspond to FIGS. 66-74for a saw handle that is approximately realized in accordance with FIGS.33-39, and FIGS. 84-92 show corresponding representations for the uppersections of pliers handles, e.g., the pliers according to FIGS. 51-58.With respect to FIGS. 84-87, it must be noted that this pertains to anupper section of pliers according to the section 162 in FIGS. 51-55, andthat the position of the longitudinal sections is chosen in accordancewith the cross section K in FIG. 88a. In addition, the longitudinalsections, in contrast to the corresponding illustrations (e.g., FIG.40-43), are respectively illustrated in a position that is turned aboutthe z-axis by 180°.

[0132] The tables according to FIGS. 95a, 95 b and 96 a, 96 b indicatethe dimensions for the saw handle according to FIGS. 75-83 and thepliers handle section according to FIGS. 84-89, analogously to FIGS.94a, 94 b.

[0133] The invention is not limited to the described embodiments and canbe modified in several ways. This applies, in particular, to theindividual design of the various handles described with reference to thefigures and the dimensions selected for a certain group of hands. Anoptimal handle for a large hand has a larger total volume than that fora small hand. In addition, other criteria may be used for categorizingthe handles into the respective groups, in particular, if dimensionsother than those indicated in the figures are deemed practical forergonomic reasons as the result of a series of tests. With respect tothe cross sections, it should be noted that the handles are preferablyoval, egg-shaped, circular, elliptical or the like in all regions inwhich they come in contact with the hand of the user. However, thehandles also may have different shapes and, in particular, be providedwith conventional finger depressions or the like in the lower sections.In particular, it is possible to select the angular ranges shown in FIG.12 differently, wherein a range of approximately 315°-90° is deemedparticularly effective with respect to the angle of the describedcurvature. However, this does not prevent the handles from containingcorners at the locations at which the less-stressed hand sectionscontact the handle. In addition, the dimensions of the handles in thedifferent groups of hands selected for the purpose of the inventionpreferably have a ratio of S:M:L=43:46:48. This ratio refersspecifically to the dimension L0.1, but other group classifications canalso be chosen if so required. It is also practical to incorporate theminimum and maximum values for the curvature contours in the region ofthe various cross sections into the design. For example, the radii R10,R12 preferably have a length between 10 mm and 30 mm while the radiiR11, R13 preferably have a length of approximately 15 mm-30 mm. In thiscontext, it is also advantageous to vary the remaining dimensions of thecorresponding handle in the same percentile ratio if the sizes arechanged from group to group or even within the same group, e.g., if thelength L0.1 is changed. A comparison of tables 93 a-96 c shows that thelength of the center part is approximately 50% of the hand width for alldescribed handles. In addition, the curvature radius R2.1 lies between50 mm and 120 mm and the curvature radii R2.2 and R2.4 lie between 50 mmand 150 mm for all handles. Surprisingly, these dimensions which areparticularly important for the coupling position are essentiallyidentical for all handles. The sectional drawings and tables describeexamples of several advantageous handle designs. In addition, the scopeof the invention not only includes the described handles, but also thetools manufactured with said handles and sets that contain severaldifferent handles or tools and that are assigned to the same functionalparts. In this case, the sets may, depending on the respectiverequirements, comprise handles and/or tools provided with handles forright-handed and/or left-handed users, as well as tools other than thosedescribed above. It goes without saying that the individualcharacteristics may also be applied in combinations other than thosedescribed above.

What is claimed is:
 1. Handle for hand and garden tools which causes apreferred coupling position of an assigned group of hands when therespective tool is used, with a first section (42, 162) that isessentially intended for contacting the palm (33), and with a secondsection (43, 163) that is essentially intended for being encompassed bythe finger joints, wherein the two sections (42, 162; 43, 163)respectively lie on one side of an imaginary longitudinal axis (39,164), wherein the first section (42, 162) contains a distal part (50,168) that is intended for being encompassed by the thumb bridge (26)between the thumb (20) and the index finger and assigned to a handlebeginning, a proximal part (54, 170) that is intended for contacting theball of the hand root (29) and assigned to a handle end, and a centerpart (52, 169) that lies between the distal part and the proximal part(50, 168; 54, 170), wherein said center part has a pronounced radiallyoutward directed curvature (57, 171) that extends over at least part ofits circumference and is intended for snugly adjoining the palm (33),and wherein said curvature has a surface, the distance of which from thelongitudinal axis (39, 164) is at its greatest in a maximum (59, 178)that is situated in a central region of the curvature (57, 171) anddistinctly decreases from this maximum to the distal and proximal parts(50, 168; 54, 170), characterized by the fact that a length (L0.1) ofthe center part (52, 169) amounts to between 45% and 55% of the handwidth (B) of the assigned group of hands (19), and by the fact that thecurvature (57, 171) has—if viewed in a longitudinal section thatcontains the longitudinal axis (39, 164)—a curvature radius (R2.1) of60-120 mm in the maximum (59, 178).
 2. Handle according to claim 1,characterized by the fact that the first section (42, 162) lies above animaginary central plane (yz-plane) that includes the longitudinal axis(39, 164), with the second section (43, 163) lying below this imaginarycentral plane.
 3. Handle according to claim 2, characterized by the factthat the maximum (59, 178) lies in a plane (xz-plane) that extendsperpendicular to the central plane and includes the longitudinal axis(59, 164).
 4. Handle according to claim 2, characterized by the factthat the maximum (point 137) lies in a plane that is arrangedperpendicular to the central plane (xz-plane) and spaced apart from thelongitudinal axis.
 5. Handle according to one of claims 1-4,characterized by the fact that the surface of the curvature (57, 171)contains a generatrix that extends from the distal to the proximal part(50, 168; 54, 170), with said generatrix representing the geometriclocation of all points that have the greatest distance from thelongitudinal axis (39, 164) in the center part (52, 169) in all crosssections (B-B) along the longitudinal axis.
 6. Handle according to claim5, characterized by the fact that the generatrix is a plane curve. 7.Handle according to claim 5, characterized by the fact that thegeneratrix is a three-dimensional curve (155, 156).
 8. Handle accordingto claim 7, characterized by the fact that the points (133-143) of thethree-dimensional curve (155, 156) partially lie on one side of a planethat extends perpendicular to the central plane (xz-plane) and includesthe longitudinal axis, with part of the aforementioned points lying onthe other side of said plane.
 9. Handle according to one of claims 1-8,characterized by the fact that all generatrices of the surface of thecurvature (57, 171) have a convex progression.
 10. Handle according toone of claims 1-9, characterized by the fact that the proximal part hasa surface contour that continuously decreases from the center part tothe proximal end.
 11. Handle according to one of claims 1-9,characterized by the fact that the proximal part (54, 170) has acontinuously concave surface contour from the center part (52, 169) tothe proximal end.
 12. Handle according to claim 10 or 11, characterizedby the fact that a length LIII. 1 which is measured between the maximum(59, 178) and a proximal end (46) amounts to 50-55% of the hand width(B) of the assigned group of hands.
 13. Handle according to claim 10 or11, characterized by the fact that a length LII.1 which is measuredbetween the maximum (59, 178) and the minimum (61, 180) or a centralregion of the proximal part (54, 170), respectively, approximatelyamounts to 33-37% of the hand width (B) of the assigned group of hands.14. Handle according to one of claims 1-13, characterized by the factthat the distal part (50, 168) has a continuously concave surfacestructure from the center part (52, 169) to the distal end.
 15. Handleaccording to one of claims 1-14, characterized by the fact that thecenter part (52, 169) has—if viewed in the form of longitudinalsections—gradually decreasing curvature radii (R2.3, R2.4) on both sidesof an imaginary plane that extends through the maximum (59, 178) andincludes the longitudinal axis (39, 164).
 16. Handle according to one ofclaims 1-15, characterized by the fact that at least one of the lengths(L0.1, LI.1, LII.1 and/or LIII.1) is realized in accordance with one ofthe tables shown in FIGS. 93a-96 c.
 17. Handle according to one ofclaims 1-16, characterized by the fact that at least one additionaldimension (LI.2-LIII.4, A1A-A3D, R1.1-R3.4, R1.10-R3.13) is realized inaccordance with one of the tables shown in FIGS. 93a-96 c.
 18. Handleaccording to one of claims 1-17, characterized by the fact that itessentially has a continuously egg-shaped, oval or elliptical crosssections in the longitudinal direction.
 19. Handle according to one ofclaims 1-18, characterized by the fact that the handle is realized inone piece, and by the fact that the first section (42) is integrallyconnected to the second section (43) by an inner section (44). 20.Handle according to one of claims 1-18, characterized by the fact thatthe handle consists of two pieces, wherein the first section and thesecond section (162, 163) respectively form part of a separate handlepart, and wherein the two handle parts are separated by an intermediatespace.
 21. Handle according to claim 20 for pliers, characterized by thefact that the curvature is realized such that its maximum lies closer tothe proximal part than to the distal part.
 22. Handle according to claim20 or 21, characterized by the fact that the first section (162) and thesecond section (163) are essentially realized identically and in alaterally reversed symmetric fashion referred to a central plane(yz-plane).
 23. Handle according to one of claims 20-22, characterizedby the fact that it has continuously elliptical, oval or egg-shapedcross sections if imaginary surfaces along the longitudinal axis (164)which connect lateral regions of the sections (162, 163) are included.24. Handle according to one of claims 1-23, characterized by the factthat it is assigned to a group of small hands and its dimensions are atleast partially realized in accordance with one of the tables shown inFIGS. 93a-96 c.
 25. Handle according to one of claims 1-23,characterized by the fact that it is assigned to a group of large handsand its dimensions are at least partially realized in accordance withone of the tables shown in FIGS. 93a-96 c.
 26. Handle according to oneof claims 1-25, characterized by the fact that it is assigned to a groupof medium hands and its dimensions at least partially have values thatlie between those for the groups according to claims 24 and
 25. 27.Handle according to one of claims 1-26, characterized by the fact thatthe curvature (57, 171) extends in at least two directions that lieperpendicular to one another and is essentially defined with respect toits three-dimensional shape and size by a combination of the surfacecontour with the radius R2.1 which extends in an xz-plane at least overthe length (L0.1) in the upper section (42, 162) of the center part (52,169), the surface contour with the radius R2.3 and/or R2.4 which extendsin a yz-plane, the radii 2.10 and R2.13 and/or R2.14 which define thecross-sectional contour in the maximum (59, 178) of the center part (52,169) and the eccentricities AII.1 and AII.3 and/or AII.1 and AII.4. 28.Handle according to claims 1-19, characterized by the fact that it has,in the region of the center part (52, 169), the curvature radii R2.2 andR2.5 of 60-150 mm, respectively in a plane 2 of 90° relative to theplane with the curvature radius R2.1 and in a plane 5 of 45° relative tothe plane with the curvature radius R2.1.
 29. Handle according to one ofclaims 1-28, characterized by the fact that it contains a thumb supporton the upper side of the distal region, wherein said thumb support isrealized in the form of a trough or flattening (83, 87) that extendsparallel or slightly oblique referred to the yz-plane and/or a lateraltrough or flattening (101) that extends slightly oblique referred to thexz-plane.
 30. Handle according to one of claims 1-29, characterized bythe fact that, in two-part handles, the region of the lower section(185) which is intended for supporting the fingers is largely realizedcylindrically and only has a slight curvature in the direction of thelongitudinal axis, wherein the upper section (184) has the pronouncedconcave-convex-concave curvature that extends in the direction of thexz-plane and in the direction of the yz-plane.
 31. Handle according toone of claims 1-30, characterized by the fact that a handle forleft-handed users is realized in a laterally reversed fashion referredto a handle for right-handed users.
 32. Handle according to one ofclaims 1-31, characterized by the fact that its cross-sectional surfacesare defined by radii RA.10-RC.14, wherein the radii R.10 and R.12 liebetween 12 mm and 30 mm, and wherein the radii R.11 and R.13 lie between15 mm and 30 mm.
 33. Handle according to one of claims 1-32,characterized by the fact that the handle has an asymmetric shape forright-handed users and for left-handed users.
 34. Handle set for a handand garden tool which causes a preferred coupling position of the handwhen the tool is used, characterized by the fact that the set contains apreselected number of handles (38, 78, 86, 106, 160) according to one ormore of claims 1-32, wherein the shape and/or size of each handle (38,78, 86, 106, 160) predetermines the preferred coupling positions of thehands of a different group of hand sizes and/or hand shapes.
 35. Handleset according to claim 34, characterized by the fact that it contains atleast two handles with different sizes.
 36. Hand or garden tool with afunctional part and a handle, characterized by the fact that the handle(38, 78, 86, 106, 160) is realized in accordance with at least one ofclaims
 133. 37. Hand or garden tool set, characterized by the fact thatit contains a series of hand or garden tools with one and the samefunctional part (64, 105, 108), but different handles (38, 78, 86, 106,160), wherein the shape and/or size of each handle (38, 78, 86, 106,160) predetermines a preferred coupling position of the hands of adifferent group of hands.
 38. Hand or garden tool set according to claim37, characterized by the fact that at least two handles (38, 78, 86,106, 160) with different sizes are provided for each functional part(64, 105, 108).